X370 Taichi upgrade 2700X->3950X no boot, no fans

I registered just to say thank you all.

I went from a 2700x to a 3950x and couldn't boot. Was in the error code loop. The magic for me was removing the second video card. I started with removing all but 1 stick of ram and when that didn't work, pulled the 2nd card. After that battery pull and replace... viola. I put the card back in, then the other 3 sticks of memory and was good after that.

Thanks again!

sp00nz wrote: Any settings I should consider adjusting before installing the 32GB DIMM?

I thought datonyb's advice of 1.4v would have nailed it to success.

if still not, then make sure the single 8GB stick voltages are
Dram 1.4V or more, all the all up to 1.45V is safe, especially just to test boot.
then

don't load XMP yet, don't run 2666mhz, not even 2133mhz, instead try 1866mhz, or whatever lowest possible.

SOC_V 1.2v this is default when high speed ram in used, but when 2133mhz is in used, then SOC_V drops of 0.8V only, This is why after swap in 32GB sticks, completely not enough to boot. Use 1.2V for SOC like the trick advice by datonyb.

CLDO_VDDP default is 900mv = 0.9V, but it can go easily to 1.05V, so try this also, this is the infinity fabric high way voltage.

32GB sticks may require more voltages.

finally try bios 6.20A or 6.20B, they are not out for no reason I think.

I had significant stability problem with 6.20, for two whole months I rejected to use 6.20A, but once upgraded, very stable, and very easy to overclock ram. I've got 3600 fast A0 PCB 1.38v, and 3733 safe 1.4V, all as per 1usmus calculator.

boot with the 8gb
change ram voltage to 1.4 volts
save exit reboot
save and exit again then fit one 32gb stick to slot a2 and try it

I had bad luck with 6.2, suspect because I didn't load default bios before flash from 6.1, had so much instability problem, finally solved when up bios to beta 6.20A. You could give is a try. There's beta 6.20B also, some say very good ram compatibility.

sp00nz wrote: Will try more aggressive clearing of the CMOS by removing battery, etc. and report back. cx5 wrote: Just in case, what's your full detailed spec? PSU not strong enough??? It's an Antec EA-750 Platinum, so probably fine. As for everything else: Two M391A4G43MB1-CTD DIMMs (2x32GB Samsung M-die), a 10Gbe card in PCIE5, an Optane 32GB in M2_1, a few SATA drives, and a Vega 64 in PCIE3 (not PCIE2!). I moved the GPU to PCIE3 during this swap so I could more easily access the CPU which has a monster NH-D15 on it. Switching it back to PCIE2 is probably something worth trying too.

I forgot to mentioned, my clear cmos problem includes removing battery not effective. I write again，removing battery does NOT clear cmos in my case. What a drag ......

Oh, 750w, no problem then I think.

I used to run Vega 64 on PCIE3 like you, no lag detected. My reason is to allow Optane900p closest to CPU enjoy least latency on every program call 24/7, since GPU for game is not on 24/7.

Good luck !!!